"Horn OK Please" Did you know that this phrase was not always a mere decorative whim of Indian truck drivers. It originated as a serious cautionary indication during the World war II. Kerosene fueled trucks were used then for movement of troops. Highly unstable in nature, Kerosene would cause the trucks to explode, at the slightest accident, hence it was painted on them, "Horn Please, On Kerosene".
You must have also witnessed another famous phrase "OK TATA BYE BYE". The theory behind this phrase is that as most of the Indian trucks are manufactured by TATA, and the word TATA is also synonym to Bye. Wishing someone Goodbye, one commonly says OK Tata.
However, I still do not know why some quotes are written behind the Indian trucks. In some trucks, they are written in a very colorful and innovative way. Someone told me that they are written to entertain and to relax the stressed drivers. What do you think?